90Y is a beta-emitting isotope which is finding uses in radioimmunotherapy (RIT) for the treatment of cancers such as Hodgkin's disease. 90Y is the daughter product of 90Sr, a common isotope produced during the fission of 235U. Abundant supplies of 90Sr exist, making 90Y a very attractive isotope for medicinal applications. However, the 90Y needs to be free from the long-lived parent to avoid accumulation of90Sr in bone and other tissue. Current separation techniques use organic ion exchange resins and complexants to produce pure 90Y. Though effective, these methods require specialist facilities and the organic materials used in the separation are prone to radiation damage. Consequently, the 90Y must be produced at a central location and shipped to the point of use. A more attractive method would be to manufacture a 90Sr/90Y generator to allow 90Y to be generated at hospitals and medical research facilities on demand. Inorganic ion exchange materials are the critical part of such a generator since any absorber must be radiation stable, highly selective for 90Sr, but have negligible selectivity for 90Y. Phase I will evaluate a number of well characterized, strontium-selective inorganic ion exchangers for use in the separation of 90Y from 90Sr. Radiotracers will be used to ensure the tests closely mimic generator conditions. Phase II will involve testing with high levels of 90Sr at Pacific Northwest National Laboratory and will lead to the production of a user-friendly, prototype 90Y generator. PROPOSED COMMERCIAL APPLICATIONS: A 90Sr/90Y generator will facilitate research in the medical applications of 90Y by improving the availability of the isotope. Isotope costs will also be reduced, fueling further research in the use of 90Y for cancer treatment. The commercial market is likely to be millions of dollars per year if a generator can be successfully developed.